This disclosure relates to a fuel cell pressure regulator system using recycled fuel. More specifically, the disclosure relates to a freeze tolerant fuel cell pressure regulator unit and fuel recycle line.
A fuel cell includes an anode and a cathode that respectively receives a fuel and an oxidant, such as hydrogen and air. Some fuel cells incorporate a fuel recycle line in which unused hydrogen from the fuel cell anode is recirculated back to an anode inlet.
Water is a byproduct of the chemical reaction within the fuel cell, and water may also be used as a coolant within the fuel cell. Depending upon the type of separator plate used within the fuel cell, the recycled fuel may be laden with moist air. Accordingly, various features within the fuel cell may become frozen in cold weather conditions. If ice blocks certain passages within the fuel cell, the fuel cell cannot be restarted. The fuel cell must also be capable of being started in freezing conditions at various tilt angles to which a vehicle may be commonly subjected.